1. Field of the Invention
The present invention relates to a compressed video decoding apparatus which is capable of decoding video bitstream containing progressive (non-interlaced) pictures which are different from the existing interlace pictures a television system.
2. Related art of the Invention
The current existing television systems in the world are NTSC, PAL and SECAM. All this systems are interlace display system which can be annoying at times and also weakens the human eyes. Some manufacturers had tried to resolve this by using double line scan. In double line scan, each line of the picture is scanned twice to produce a flicker free output. However, this only solves half the problem. This is because the artifacts such as `steps` appear at the edge of pictures, giving the appearance that the picture is blocky. During the last few years, there have been attempts by some broadcasters and manufacturers to rectify these problems by proposing a new television standard called the High Definition Television Standard (HDTV). However, high costs and complexity in both the receiver and broadcasting equipment discourage most consumers and broadcasters. As a result wide acceptance in the real world had not been very successful.
Recently, the Moving Pictures Expert Group (MPEG) had defined a new video compression Called the MPEG2 which is capable of compressing pictures upto 200 times and therefore open the path for digital broadcasting. However, MPEG2 video compression chips that were delivered as a result of this standard mostly use only Main Profile at Main Level (MP@ML) and display the standard interlace output. This therefore does not completely solve the problems mention above as there is no improvement in either picture resolution nor display rate.
Current existing standard systems can only display interlace output. This type of flickering display can be rather annoying to users and damaging to the eyes. In addition the resolution is low and interfacing to computer graphics which is generally of high resolutions is unsatisfactory. Current analog transmission system is also lower in quality and reliability compared with digital transmission. However, digital transmission bandwidth requirement is enormous and some compression is required. HDTV systems which can solve most of the above problems are too high in cost for both broadcasters and consumers.